English cites the Dodd-Frank Act, which created the bureau, saying that as deputy director, she became the acting director under the law when Cordray resigned.

She also argues that the federal law that the White House says supports Trump's appointment of Mulvaney doesn't apply when another statute designates a successor. Her suit seeks a temporary restraining order to block Mulvaney from taking over the bureau.

Mulvaney has long criticized the bureau as an example of bureaucracy run amok.

In a statement, White House spokeswoman Sarah Huckabee Sanders attributed the suit to politics and referred to an apparent internal bureau memo, in which its top lawyer concluded that Trump could appoint Mulvaney.

"There should be no question that Director Mulvaney is the Acting Director," Sanders said. "It is unfortunate that Mr. Cordray decided to put his political ambition above the interests of consumers with this stunt."

The suit comes one day after the Justice Department issued a memo saying that because the bureau is under the authority of the executive branch, the president has the power to name its acting director.